Safety mechanism for continuous casting apparatus



c. THULIN 2,145,438

SAFETY MECHANISM FOR CONTINUOUS CASTNG APPARATUS hn. 3l, 1939.

Filed Aug. 25, 1957 2 Sheets-Sheet l Jan. 31, 1939. c. THULIN SAFETY MECHANISM FOR CONTINUOUS CASTING APPARATUS Filed Aug. 25, 1937 2 Sheets-Sheet 2 Patented Jan. 31, 1939 SAFETY MECHANISM FOR CONTINUOUS C ASTING APPARATUS Clarence Thulin, Waterbury, Conn., ass-ignor to Chase Brass & Copper Co. Incorporated, Waterbury, Conn., a corporation oi' Connecticut Application August 25, 193i, sei-iai No. 160,195 4 claims. (ci. ca -57.2)

This invention relates to apparatus for' continuously castingmetal in the form of rods, tubes, bars, or the like. and more particularly to safety features for such apparatus.

One of the objects of the 'present invention is to provide a continuous casting apparatus hav'- ing superior means whereby the failure of such a feature of the apparatus as might cause the accidental release or dumping of molten metal from the crucible or container will automatically effect the stoppage of the apparatus.

Another object is to provide continuous casting apparatus having superior means whereby the casting apparatus may be automatically stopped in the event that a failure occurs in the casting passage or adjacent feature of the apparatus.

With the above and other objects in view,as rwill appear to those skilled in the art from the present disclosure, this invention includes all features in the sai-d disclosure' which are novel over the prior art and which are not claimed in a separate application. p

In the accompanying drawings:

Fig. l is a schematic view of an apparatus illustrating an embodiment of the present invention,

' of crucibles and the like.

with the crucible or container, the casting or forming die, the cooling chamber and associated parts in vertical central section and showingthe safety mechanism in its inoperative position;

Fig. 2 is a View corresponding to Fig. 1 but showing a fracture as having occurred in the retaining member of the casting-unit to thus eiect the operation of the safety mechanism and the stoppage of the withdrawing-rolls; and

Fig. 3 is a transverse sectional view taken on the line 3-3 of Fig. 1.

`The continuous casting apparatus herein chosen for the purpose of illustrating the present invention includes a cup-shaped container or Crucible generally designated by the reference number 2li and which may be formed of any suitp able material, such for instance as a clay-graphite composition commonly used in the manufacture Such container or Crucible 20 includes a substantially-fiat bottomwall 2|- and an upstanding annular side-wall 22. The said container 20 rests upon a platform 23 having a vertical passage 24 therethrough in line with the central axis of the said container. Preferably the platform 23 just lreferred to is of a heat-insulating character and may be mounted upon any suitable support (not shown).

The bottom-wall 2| of the container or crucible 20 is provided with an axial passage 25 in which is seated a retaining-member 26. The said retaining-member may be formed of a suitable refractory material and is provided as shown with an externally-threaded tubular shank 2l projecting belowy the under surface of the bottom-wall 2| of the container 20.

Threaded onto the downwardly-projecting por- .tion of the externally-threaded shank 21 of the' retaining-member 26 is the internally-threaded coupling-sleeve 28 of a cooling-chamber generally 1U designated by the reference character 29 and which is preferably formed of copper or other high heat-conductive material. Secured to one side of the cooling-chamber 29 by brazing, silver solderingor the like is a water-head 30 having a l5 water-inlet passage 3l and a water-.outlet passage 32 respectively communicating with an inletpipe or tube 33 and an outlet-pipe or tube 3i. The cooling-chamber 28 may assume a wide variety of forms and as herein shown its interior is 20 provided with a series of fins 35 to facilitate the transference of heat to the water or other coolant and is provided with a vertically-extending partition 4fili which divides the interior to a degree sufficient to compel most of the coolant to flow 25 entirely around the ring-like compartment before discharging through the outlet passage 32 and tube 34.

Rigidly secured to the periphery of the coolingchamber 29 by means of brazing, soldering or in 30 any other suitable manner is a lug 3l having a downwardly-opening threaded socket 33 therein, winch latter receives the externally-threaded upper end of a vertical actuating-rod 3Q having a ange-like head ill at its lower end. The head t@ 35 of the actuating-rod 39, just referred to, is normally engaged by the upper end of a verticallyadjustable thrust-screw All carried in one of the arms 42 of an actuating-lever, generally designated by the reference character 43, and includto ing, in addition to the arm t2, arelatively-long oppositely-extending arm 44.

The upper surface of the outer end of thearm 44 of the actuating-lever 43 is rounded as at l5 for engagement with an. antifriction roller llt a5 carried by a. Sear-lever 41 which is pivoted by means of a stud 48 upon a bracket 49, to which latter the actuatirm-lever 43, already referred to, is also pivotally connected by means of a stud bil.

The Sear-lever 41 is formed at its end remote til from the antifriction roller 46 with a scar-nose 5l which is adapted to be engaged with the upper surface of the outer end of a pivotal switch-arm 52 which is pivotally secured at one end to the bracket 49 by means of a stud 53. The switchblt arm 52 carries on its under side acircuit-closing plate 54 which is insulated from the said arm by a plate-like body of insulation 55, and which is adapted to control the iiow of current between two contacts 56 and 51 which, together with the switch-arm 52 and the parts carried thereby, constitutes a control-switch generally designated by the reference character 58 and controlling the energization of a driving-motor 59.

The contact 56 of the control-switch 56 is connected by means of a wire 60 to one terminal 6| of the driving-motor 59. The opposite terminal 62 of the said motor is connected by means oi.' a wire 63 with one of the main-line or power wires 64. The complemental main-line wire 65 is, as shown, connected by means of a wire 66 to the contact 51 of the control-switch 58, so that when the switch is in the position in which it is shown in Fig. 1, the driving-motor 59 will be energized.

Normally the container or crucible 28 is charged with molten metal 61 which flows downwardly into the upper end of the vertical castingor forming-passage 68 of a tubular forming-die 69 which extends through the retaining-member 26 and the cooling-chamber 29 in intimate thermal contact therewith. The retaining-member 26, the cooling-chamber 29 and the forming-die -69 may, for purposes of description, be designated as the casting-unit of the apparatus.

As the molten metal 61 passes downwardly through the forming-passage 68 in the formingdie 69, it will solidify within the said formingpassage at a point therein depending upon the speed at which the metal is withdrawn. For the purpose of illustration, the solidiiication zone within the forming-passage 68 may be considered to be at about the point marked 10 in the accompanying drawings. It will thus be seen that molten metal 61 is solidified before emergence from the lower end of the forming-die 69, and if desired, the extraction of heat from the molten metal to eifect its solidiiication into the solid bar 1| is effected through the lower portion of the said forming-die by the coolingchamber 29 and such additional cooling-means as circumstances may require.

The downward travel ofthe solidified bar 1| is effected by means of a plurality of withdrawing-rolls 12 mounted well below the coolingchamber 29 and propelled through suitable gearing (not shown) encased within a gear-case 13 and in turn propelled by the driving-motor 59 through the intermediary of suitable mechanical connections such as 14.

As before explained, the rate of withdrawal of the solidified bar 1| is such that the following molten metal concurrently flowing into the forming-passage 68 will solidify before such molten metal can emerge from the lower end of the said forming-passage.

In Fig. 1 is illustrated a normal condition of the apparatus during the casting operation, in which figure it will be noted that the controlswitch 58 is held in its closed position against the tension of a spring 15 by the scar-nose 5| of the scar-lever 41, so that the driving-motor 59 is energized and thewithdrawing-rolls 12 are being turned to continuously draw downwardly upon the now solidified bar or rod 1| at a predetermined rate ofspeed.

Now in the event that a breakage should occur which would occasion a slight .downward movement of the cooling-chamber 29 or associated parts, the driving-motor 59 will be stopped and hence the further downward travel of the now be stopped, as will of the container or crucible 28. Under the conditions just described, and as s own in Fig. 2, the fracture of the tubular shank 21 will permit the cooling-chamber 29 todescend to a similar degree under` the urge of gravity and the frictional pull of the solidified metal 1|.

When the cooling-chamber 29 moves downwardly, the actuating-rod 39 will be similarly moved and will, through the thrust 4|, depress the short arm 42 of the actuating-lever 43 and rock the latter about its stud 50. This rocking of the actuating-lever 43 will raise the arm 44 thereof and, through the intermediary of the parts 45 and 46, effect the lifting of the outer end oi' the scar-arm 41, so as to turn the latter upon its stud 48 in a clockwise direction. As the Sear-lever 41 is turned, as described, its searnose 5| will ride oil' of the outer end of the switch-arm 52 and permit the spring 15 thereof to act and swing the said switch-arm upwardly so as to disengage its circuit-closing.. plate 54 from the contacts 56 and 51, thereby immediately cutting oif the supply of current to the driving-motor 59 and thus, in turn, stopping further downward draft upon the solidified metal 1| The parts will now have assumed the positions in which they are shown in Fig. 2.

From the foregoing, it will be seen that by means of the present invention, one of the greatest hazards to workers and equipment incident to the use of continuous casting apparatus is automatically guarded against.

When a stoppage of the apparatus has occurred, as abo've described, and after the breakage or defect has been remedied, the parts may all be reset as illustrated in Fig. 1 and continuous casting operations again carried on.

The invention may be carried out in other specic ways than those herein set forth without departing from the spirit and essential characteristics of the invention, and the present embodiments are, therefore, to be considered in al1 respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

I claim:

1. Apparatus for continuously casting molten metal into solid bars, comprising: a molten-metal container; a casting-unit arranged to receive a continuous flow of molten metal from the said container and constructed to solidify the molten metal into a s olid bar as it passes therethrough; withdrawing-means operating on the solid bar and transmitting therethrough stress tending to rupture the casting-unit; an actuating-member mounted on a normally-fixed part of the castingunit and displaceable from a normally-fixed position by a rupture of the casting-unit; and means constructed and arranged to be actuated by the displacement of said actuating-member, for interrupting the supply of power to the said withdrawing-means. I

2. Apparatus for continuously casting molten metal into solid bars, comprising: a molten-metal container; a casting-unit having a tubular forming-die arranged to receive a continuous flow of molten metal from and extending through and beyonda wall of the said container; a coolingamena@ chamber member extending around and in heatextracting relation to the said forming-die without the said wail of the molten-metal container,

the said cooling-chamber member being sup-' ported by a portion of the said casting-unit which is disposed within and supported by the said wall of the molten-metal container; withdrawingmeans operating upon and continuously withdrawing solid bar from the said forming-die; means for supplying power to the said withdrawing-means; and means normally unrelated to the continuous casting operation and suitably-constructed and arranged to be actuated by a displacement of the said cooling-chamber member responsive to a rupturing strain imposed upon the said casting-unit by the said withdrawingmeans, for interrupting the supply of power t0 the said withdrawing-means.

3. Apparatus ior continuously casting molten metal into solid bars, comprising; a molten-metal container; a cooling-chamber member depending from the bottom wall of the said container; a retaining-member mounted in a wall of the said container; means constructed and arranged to support the cooling-chamber member from the said retaining-member in depending relation to the wall of the molten-metal container; a tubular forming-die extending through the said retaining-member and cooling-chamber member and supportably engaged by both of said members in position to receive at its upper end a continuous flow of molten metal from the molten-metal container; withdrawing-means operating continuously on the solid bar issuing from the lower end of the said tubular forming-die; means for driving the said withdrawing-means; and means normally unrelated to the continuous casting operation and constructed and arranged to be actuated by a displacement of the said cooling-chamber member due to a rupturing strain imposed upon one of the said members by said withdrawingmeans, to de-energize the said driving-means.

4. Apparatus for continuously casting molten metal into solid bars, comprising: a moltenmetal container; a retaining-member mounted in and supported by the bottom wall oi the said container; a cooling-chamber member connected to the lower end of the said retaining-member and pendantly supported thereby from the bottom wall of the molten-metal container; a tubular forming-die extending through and supported by the said retainingand cooling-chamber-members to receive at its upper end a continuous ow of molten metal from the molten-metal container to be solidified therein into a continuous-bar; withdrawing-means operating upon and continuously withdrawing the solid bar from the lower end of said tubular forming-die, the said members being constructed and arranged to transmit to the said retaining-member the strain imposed thereon by the said withdrawing-means; means for supplying power to the said withdrawingmeans; a normally-stationary actuating member mounted on the said cooling-chamber member; and means normally unrelated to the power-supply means during the continuous operation of the said withdrawing-means and arranged to be operated by said actuating-member accompanying a downward Amovement of the cooling-chamber member responsive to a rupturing strain imposed o-n one of the said .members by the said withdrawing-means, for de-energizing the power-supplying means.

CLARENCE THULIN. 

